First, I follow eur / usd, then a lot. I followed 10-12 pairs to trade which seemed good for trading. I trade with them. but it only works for short time trading. like 15 minutes or a maximum of 1 hour and for now, I prefer to trade with any partner who gives me a strong signal to open a trade. Of course I would prefer to pair up which has a lower spread than higher. But, after all, my trade is open to all couples who might match my strategy. About strategy, I use some of them. I have my main system as my trigger but sometimes I use another system for confirmation only.